Species: Astyanax aeneus, Banded Tetra, Penjamo Tetra

Astyanax aeneus (Gunther, 1860)

Banded Tetra, Penjamo Tetra

Body a moderately deep oval, tapering to rear, body depth 34-39% SL (in larger fish), strongly compressed; head length 24-32% SL; snout bluntly pointed, shorter than eye; eye large, 41-46% of head, 7.8-10% of SL: mouth oblique opens at front, not upturned; lower lip variable in shape, may be widened and flap-like, with an internal expansion; front bone (premaxilla) of top jaw with 2 rows of teeth, all 3-pointed teeth in outer row, rear (maxilla) bone with 3-4 (1-9) teeth; gill rakers 24 (19-26); dorsal fin ii, 8-9, end of dorsal fin base over anal fin origin; a small, short-based adipose dorsal fin on tail base above rear end of anal fin; anal rays iii-iv, 26 (22-30); pectoral i-ii, 10-14, extends back to over rear insertion of pelvic fin; lateral line complete, 35 (33-38) scales; scales between lateral line and dorsal fin origin 8.3 (8-9); breeding males with tubercles on scales of nape and upper head, and over much of body, and with bony hooks on all fins.

Upper head and upper 1/3 of body greenish brown, lower parts silvery white, an abrupt junction between the two colors along the side of the body; upper part of eyeball red; a dark, vertically oval humeral blotch behind top corner of operculum; an indistinct black stripe along center of rear of tail base expands to a rhomboidal black blotch at end of the base, extends as a black stripe to end of center of tail fin, color stronger on fin than body; front rays of dorsal and anal fins and tail fin usually with yellow to orange pigment.

Reaches 14 cm

Lives in coastal streams, lakes and coastal lagoons, in brackish water and mangroves; forms schools, migrates in streams.

Depth range 0-5m?

Mexico to Panama.